1. Technical Field
The disclosure relates to power supply systems, and particularly to a light emitting diode driving system.
2. Description of Related Art
Light emitting diodes (LEDs) are used as backlights of a display due to environment friendly merits and high contrast of the LEDs. Usually a plurality of light emitting diode (LED) strings, each including a plurality of LEDs connected in series, are connected in parallel in the screen. Thus, in order to maintain current balance of each of the plurality of LED strings, each of the plurality of LED strings is connected to a voltage and/or current detection circuit and a switch to detect corresponding voltage and/or current to feedback to a PWM controller. Then the PWM controller controls voltage outputted to the plurality of LED strings, and controls on and off of the switches to adjust the current flowing through the plurality of LED strings. However, the structure is too complicated, and increases costs.